Macrolactonization Reactions Driven by a Pentafluorobenzoyl Group**
作者:Guillaume Force、Anna Perfetto、Robert J. Mayer、Ilaria Ciofini、David Lebœuf
DOI:10.1002/anie.202105882
日期:2021.9
towards their synthesis, notably from seco-acids, a macrolactonization promoter system that is effective, selective, flexible, readily available, and, insofar as possible, compatible with manifold functional groups is still lacking. Herein, we describe a strategy that relies on the formation of a mixed anhydride incorporating a pentafluorophenyl group which, due to its high electronic activation enables
An effective method for the protection of carboxylic acids with a triisopropylsiloxymethyl (TIPSOCH2) group is described. The reactions of various carboxylic acids with C12H25SCH2OTIPS in the presence of CuBr2, Et3N, and molecular sieves 4A afford the corresponding triisopropylsiloxymethyl esters in good yields.
Studies on the Transesterification and Macrolactonization of 2-Pyridyl Esters by Intramolecular N-Alkylation or Metal Ion Coordination
作者:Anthony G. Barrett、Mathias U. Frederiksen
DOI:10.1055/s-2005-918476
日期:——
In a process analogous to use of the Mukaiyama reagent, Ï-hydroxyalkyl 2-pyridyl ester derivatives were converted into lactones by N-alkylation or the coordination of copper(II) triflate and transacylation of the resultant electrophilic Ï-hydroxyalkanecarboxypyridinium salts.